A beneficial discovery

I think Wi-Fi is discovered in the last 100 years has been most beneficial for people. If there is no Wi-Fi in the world, we can't download any app like WeChat or Instagram. If we play games or go in internet,  we can't without Wi-Fi, it can help us to search some important information and bring some fun things to our life. Nowadays, there are many people don't need go to office, they can work at home if there is Wi-Fi at their house. Some people are shopping at home, they can go online like Amazon. they can buy what ever they want. So, Wi-Fi is very important and beneficial for people.